Proton Exchange Membrane (PEM) electrolysis is a pivotal technology for establishing a hydrogen economy in Europe and other parts of the world. Platinum and Iridium are indispensable elements for PEM electrolyzers. Iridium is a scarce metal and supply & demand are in the balance as of today.
To meet the further demand of iridium with respect to the announced increase in electrolyzer capacities in the multi-GW range, material innovation to reduce the use of this precious metal must be implemented.
The presentation will show the current and future situation for iridium and will outline measures to ensure the ramp-up of PEM electrolysis with respect to the availability of iridium. Here, we present a material innovation in the form of Ru-based electrocatalysts with a significantly reduced Ir content. This ruthenium-iridium oxide can be adjusted in a wide range of Ir content down to less than 15 wt.% (Ir). Consequently, iridium-based electrode loadings of less than 0.1 mg/cm2 and mass activities of about 3,500 A/g are feasible. Moreover, in accelerated degradation tests those mixed-oxides have demonstrated the often-missing stability by showing low degradation rates, similar to that of pure IrO2, in up to 30,000 potential-induced stress cycles.